<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .wrap{
            width: 500px;
            height: 500px;
            border: 1px solid #000;

            /* display: table-cell;
            vertical-align: middle; */

            /* display: grid;
            align-items: center;
            justify-content: center; */
        }
        .child{
            width: 200px;
            height: 200px;
            border: 1px solid red;
            text-align: center;

        }
        .child1{
            /* position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            margin: auto; */

            /* margin: auto; */
            margin-left: 149px;
            margin-top: 149px;
        }
    </style>
</head>

<body>
    <div class="wrap wrap1">
        <div class="child child1">Hello</div>
    </div>
</body>
</html>